Referring to JP-2005-282420A, there is known a fuel injector for injecting fuel directly into a combustion chamber, for example. Specifically, JP-2005-282420A discloses a fuel injector with which fuel injected from a nozzle hole in the fuel injector is formed in a substantially hollow conical spray film shape (hereinafter “hollow spray”). This technology discloses a fuel injector with a tip part in which a nozzle hole plate is disposed. A plurality of nozzle holes are formed in the nozzle hole plate in predetermined locations, and a group of fuel jets sprayed from the plurality of nozzle holes forms the hollow spray.
A general means of describing the shape of the fuel spray (i.e., the “spray form”) is to use an opening angle inside the spray film within the hollow part of the spray as a form index, wherein the opening angle of the hollow spray is called “a spray angle.”
The fuel jet injected from an outlet of the nozzle hole is generally formed into particles due to the friction of the fuel jet with surrounding air. The fuel jet carries away the air causing the friction and surrounding air thereof.
However, the conventional technology suffers from certain disadvantages. More specifically, the conventional fuel injections may not form the hollow spray into a predetermined spray form since pressure in the hollow part inside the spray film may be lower than the surrounding air outside the spray film. Therefore, the spray angle is reduced depending on the predetermined location of the nozzle hole, and the hollow spray may not be in the predetermined form. Furthermore, an ignitable air-fuel mixture may not be formed at a spark location if the spray angle is reduced substantially and the hollow spray shape is not formed in the predetermined form.
In view of the above, there exists a need for a fuel injector that overcomes the above-mentioned problems in the conventional art. The present disclosure addresses this need in the conventional art as well as other needs, which will become apparent to those skilled in the art from this disclosure.